The present invention relates in general to tape sealing of rectangular cartons or boxes with tape courses or runs of pressure sensitive tape, and refers more particularly to tape sealing of a stationary paper board carton, which is not stiff enough and lacks tear resistant strength, with short "L" tape runs of narrow pressure sensitive tape from the vertical front panel onto horizontal panel, that is onto the carton top or bottom, where the tape course is terminated.
It is common practice to tape seal rectangular shipping cases or cartons with a continuous length of sealing tape, such as a pressure sensitive type, the tape being applied first at the front wall of the carton onto and along either or both the bottom or top wall if upper and lower sealing courses are used, and then onto the rear wall, the tape courses along the top and bottom walls overlapping and sealing infolded closure flaps in place on the carton. The tape applied at the front and rear walls provides an anchorage length to securely hold the tape lay down at the top and bottom walls so that, e.g., any imposed loading of carton contents on the bottom wall cannot breach the tape seal along that surface or the top flaps cannot readily accidentally become opened, e.g., the type of machine described in U.S. Pat. No. 4,039,367.
The "L" tape applying machines are used where shorter courses of sealing tape suffice, thereby resulting in significant savings in the quantity of sealing tape required in connection with box or carton packing operation, e.g., the type of apparatus described in U.S. Pat. No. 4,640,731
Representative of such instances are full telescopic cartons wherein a cover or lid fits over a bottom or tray member where the tray is filled with product and a companion rectangular cover member is telescoped over the base and tape sealed. The tape courses or runs with which such cartons can be sealed could follow "L" tape runs at the carton vertical panels and onto the carton horizontal panel, where the tape courses are terminated. In case of a telescopic box two or more "L" tape courses can be applied to each carton side and bottom panel.
Other instances when effective tape securement can be achieved with "L" tape runs of pressure sensitive tape is sealing of one piece tuck-in, full overlap and other widely used types of carton.
While pressure sensitive tape is widely used for tape sealing of rectangular shipping cartons, the use of pressure sensitive tape is not common on structurally weak paperboard cartons also known as chipboard cartons. More common ways of securing paperboard cartons is gluing, cellophane wrapping or shrink wrapping.
When pressure sensitive tape is used for tape sealing of chipboard cartons to make the carton temper resistant or to protect the product, the taping operation is usually performed by hand what is highly labor intensive and marked by low production rate, is not uniformed what makes it aesthetically unappealing and unnecessary costly. The reason for manual taping is that most known "L" clip applying machines are designed to apply tape to structurally sound corrugated box, cannot be used on a carton which is not stiff enough and locks tear-resistance strength.
The tape sealing apparatus described in U.S. Pat. No. 4,640,731 is designed for applying "L" tape runs of pressure sensitive tape to a forwardly traveling corrugated box. This device and manner of applying "L" tape courses of pressure sensitive tape has a number of disadvantages, viz.,
a. The device requires a machine with transporting belts to move a carton in forwardly directed travel. The device cannot function without a machine that incorporates transporting belts. PA1 b. The device doesn't have a taping area where the vertical and horizontal carton walls held together during tape application. Failure to squeeze together vertical and horizontal walls of structurally weak carton can result in a poor seal with a loop of pressure sensitive tape formed between the vertical and horizontal carton walls. PA1 c. The device does not have a tape pre-pull mechanism. The tape is applied directly to the wall of the carton and by moving on transporting belts the carton pulls and unwinds the tape from the tape stock. The resistance of the tape being unwind off the tape roll and pulled through the taping apparatus can be too great for a structurally weak carton what can result in collapse of the carton walls. PA1 d. The device requires for the carton to be rigid enough to compress the spring loaded arms of the taping mechanism. PA1 a. The device operates only with a high performance filament tape. It cannot operate with a regular, commonly used film tape. PA1 b. The device can apply only a long piece of filament tape (4.5" long "L" tape course) what can be unacceptable for small size cartons. PA1 c. The use of reinforced filament tape for tape sealing of structurally weak cartons, which cannot be used to carry large weight, is wasteful of reinforced filament tape. PA1 d. The box introduced into the taping area has to be rigid enough to compress two spring loaded sensing devices in order to activate taping mechanism. PA1 a. The device requires for the carton to be pushed across the top of the unit, what is inconvenient and labor intensive. PA1 b. The device requires for the carton to be rigid enough to compress the mechanical spring loaded arms of the mechanism, what is not the case on a structurally weak carton. PA1 c. In operation the device can use only small rolls of pressure sensitive tape located inside the frame of the S-35 Manual Box Closer, what becomes a big inconvenience in high volume industrial applications. PA1 d. The device doesn't have a taping area where the vertical and horizontal carton walls held together during tape application. Failure to squeeze together vertical and horizontal walls of a structurally weak carton can result in a poor seal with a loop of pressure sensitive tape formed between the vertical and horizontal carton walls. PA1 e. The device does not have a tape pre-pull mechanism. The tape is applied to the front wall of the carton and the carton, pushed by the operator through the taping mechanism, pulls and unwinds the tape from the tape stock. The resistance of the tape being unwind off the tape roll and pulled through the taping apparatus can be too great for the structurally weak carton, what can result in collapse of the carton walls.
A device for applying "L" tape courses of a reinforced filament tape to a stationary box being marketed by 3M Company of St. Paul, Minn. under trade name of 3M Matic S-847. This device and manner of applying L-clip has a number of disadvantages, viz.,
Another product marketed by 3M Company of St. Paul, Minn. is S-36 Manual Box Closer that can apply film as the carton is pushed across the top of the unit. This device and manner of applying "L" clip has a number of disadvantages, viz.,
It is therefore desirable that an improved apparatus to be provided for forming a "L" clip courses of tape on a carton, which is not stiff enough and locks tear resistance strength and apparatus that do not have the undesirable shortcomings noted above, It is also understood that the introduced taping apparatus that can apply "L" clip courses of tape on the carton which is not stiff enough and locks tear resistance strength can also be used in sealing of structurally sound cartons.